Question

if a + b= 7 and AB =10 find a- b​

Answer 1

±3

Given, (a+b)=7, ab=10

Squaring both sides

⇒(a+b)

2

=7

2

⇒a

2

+b

2

+2ab=49

⇒a

2

+b

2

=49−2(10)

⇒a

2

+b

2

=29

Now,

(a−b)

2

=a

2

+b

2

−2ab

=29−2(10)

=29−20

=9

∴a−b=

9

=±3

Answer 2

Answer:

(a+b)²-(a-b)²=4ab

(a-b)²=(a+b)²-4ab

=7²-4*10

=49-40

(a-b)²=9

a-b=√9=3

Hope its help u....